The use of torque wrench systems to loosen and tighten bolts and nuts within the petroleum industry such as on drilling risers for off-shore drilling contractors is well known. Drilling equipment can or often consists of a series of riser sections joined together in a string and lowered onto a drilled well. Each joint of riser is joined together using flanges. Each riser flange has either 6 or 8 fastener assemblies depending on the model or design criteria. Some riser flanges have fasteners on two separate pitch circle diameters PCD. The fastener assemblies have bores on each flange which are aligned in use. The bottom bore houses a threaded nut for retaining the threaded fastener. The flanges are mechanically coupled by hydraulic torque wrench assemblies driving threaded fasteners into the aligned bores for mechanically coupling the flanges together.
The process of tightening and loosening bolts generally involves two stages: a high torque phase and a low torque phase. This two stage system works with a wrench during the stages of low torque and a ratchet during the stage of high torque. There have been a number of recent attempts to improve upon the efficiency of torque wrench systems by the use of a single device incorporating both mechanisms. However these recent developments are still problematic with regards reliability and performance. Further, recent attempts continuously expose operators to a number of potential hazards such as exposure to high pressure hydraulic lines and quick disconnect couplings, notwithstanding exposure to a variety of known pinch points. The tools also often require stripping down to allow the same tool to make up and break out the same fastener which is a time consuming process. Further problems exist where the reaction arm of the existing tools react against the flange in such a way that a lot of torque is lost through slippage. Furthermore, socket cracking is a common occurrence on the existing tools as a result of misalignment of the torque forces acting through the tool.